log4j can be downloaded from the Apache Web site. The download is available in two formats, tar.gz and zip. Both downloads contain the source code for the log4j API, documentation, examples, and distributable log4j executables in the form of .jar files. Extract the files to a location of your choice. The source code is supplied, in case you want to do a build for yourself. The build can be done with the help of Ant and the build.xml files that are provided; you can customize the build script if required. The build will produce the log4j-1.2.4.jar file in the dist/lib directory if built using the dist target. Note that for the build to be successful, you will need to have the Java Management Extensions (JMX) API in your classpath, as well.